Ramps/Climbing the Platform

[Travis Hoffman]

[Aside - this is the second time I've written up a post for this. I clicked the post button and received the dreaded 5:00 AM backup message - all content lost. Hey Brandon - a GREAT feature would be for the website to capture our post text and save it just prior to posting so it will still be there when we click the back button after a posting issue. Is that even possible?]

Please discuss your design ideas and planned methods of climbing the platform and the related strategy of providing ramps or other mechanisms to assist others in climbing the platform. I've not seen much discussion in this area (perhaps for good reason).

Before doing so, please look at the following two pictures of the kitbot on the platform - visualize bumpers adding 6.5" of length and width to the robot that you see:

http://www.chiefdelphi.com/media/photos/34537?
http://www.chiefdelphi.com/media/photos/34538?

My observations:

• Not a whole heck of a lot of room up there, huh, especially along the narrow 32" platform dimension - that will be the "landing zone" for any robots driving up a ramp-assist robot. The thought of The Price is Right game "Cliff Hangers" comes to mind, complete with yodeling and loud, crashing sounds. It also evokes images of many large, 4WD lemmings plunging off the cliff into the sea.
• Unless I've misinterpreted the field drawings and Team Update #3, to climb onto the platform from the bump sides, the so-called "easy" way up, your frame + bumpers will have to be less than 32 inches wide. That's a relatively compact robot (25.5" frame dimension or smaller, with a similar reduction in the other dimension to retain proportion). If you want to climb onto the platform from the bump, you will make the packaging of all your robot components even more of a challenge.
• If somehow a "standard-sized" robot manages to get onto the platform, I wonder how that robot will manage its "junk in the bump[ers]". That is, how will it keep its bumpers from sticking out past the platform and interfering with partner robots trying to hang from the ground? Will the robot be designed to be able to have some of its wheels/tread hang off the edge of the platform to give its partners more room? Will those wheels/tread remain above the platform plane, retaining the robot's ELEVATED status? Is there a risk that the hanging robot might push the platform robot off the platform if the platform robot cannot get out of the way?

I'm going to suggest that if climbing the platform is one of your primary strategies, you keep all of these points in mind - ESPECIALLY the considerations for any partners trying to hang.

Finally, something tells me the GDC didn't accidentally arrive at these platform dimensions. If they did, well...it's better to be lucky than good.

[jts]

We're considering such a strategy. Currently, we are looking into an effective way to climb onto the platform and from there how to deploy ramps with the goal of having one robot drive on top of us and the other lifted by raising the ramp (winch). Tipping over during the lifting of the second alliance partner is another concern in addition to just getting there and then successfully deploying ramps.

Would anyone with experience from 2007 care to chime in with advice on lifting mechanisms for raising a ramp?

[Jon Stratis]

It seems to me that any system sufficient enough to take your robot onto a 20 inch high platform is going to be just as complicated (or more so!) as a system to grab the bar and hang. Even if you try to go from the bump to the platform, that's still a good 6-8 inches, and most likely not an easy task, especially with the bumpers in the way.

For those trying to decide which is easier, hanging or platform... Just know that we have an amazingly simple mechanism that gets us hooked and elevated quickly while only using 1 CIM and no other motors.

[MrForbes]

Did anyone else notice the rollers on the TOWER drawings? Fun stuff!

[Travis Hoffman]

Originally Posted by squirrel

Did anyone else notice the rollers on the TOWER drawings? Fun stuff!

Ahh, so that's what those horizontal bars mounted above the tunnel openings at platform level were. I thought they were fixed in place.

I see no reference to them in the Arena document. Has there been any significant discussion of these items on Chief? Seems like a pretty important element of the platform/tower to consider.

Can anyone point out an existing online photo of the official kickoff field tower that shows these rollers up close?

[jts]

Originally Posted by eagle33199

It seems to me that any system sufficient enough to take your robot onto a 20 inch high platform is going to be just as complicated (or more so!) as a system to grab the bar and hang. Even if you try to go from the bump to the platform, that's still a good 6-8 inches, and most likely not an easy task, especially with the bumpers in the way.

The idea was to create a system that could score 8 points, 2 for getting our robot on top of the platform and 6 more for having two additional robots supported by our 'bot above the plan of the platform (via a ramp extending towards the center of the field). It is thought by many on the team that 8 points would be sufficient to win many matches, if not most.

As for the rollers on the tower structure, we would be accessing the platform from the bump under current designs.

[Bruceb]

Rollers? Where?
Bruce

[jts]

They're called for in document GE-10029_revB.

[aldaeron]

Originally Posted by jts

The idea was to create a system that could score 8 points, 2 for getting our robot on top of the platform and 6 more for having two additional robots supported by our 'bot above the plan of the platform (via a ramp extending towards the center of the field). It is thought by many on the team that 8 points would be sufficient to win many matches, if not most.

As for the rollers on the tower structure, we would be accessing the platform from the bump under current designs.

So you are talking about a ramp that holds two 38" long robots that each weight 150 lbs back to back on a long ramp? I assume you are planning to be a herding bot of some sort since you will not have much weight left to do anything else

I would look at three things:

1) How heavy of a ramp you need to support the two bots (realize the first bot is 150lbs*19in = 2850 in-lbs and the second is 150lbs*53in = 7950in-lbs) PLUS the weight of the ramp?

2) I realize you only have to lift and hold one inch, but will the motors (even with high gearing) be able to put out that much torque?

3) What will keep the robot from teetering over? If you clamp to the vertical bars as a support, how will you actuate that clamping (do you have enough motors left after using most of them to lift the ramps?)? Also, how long will it take to get setup? 20 sec? 30 sec?

Seems like a good plan to get 8 points consistently if designed correctly. But what if the other bots can't get to you at the end of the game for whatever reason?